Microsoft Outlook is quite frequently used in combination with Exchange Server. In fact, the duo makes for the standard emailing platform that most organizations use today. However, often while trying to connect to the Exchange Server through the Outlook client, users face some errors which baffle as well as irritate them. In this article, we’ll be highlighting one such particularly notorious error along with its solution.

Problems while connecting Outlook to Exchange

If you’ve been working with Outlook for long, you would definitely have connected to the Exchange Server at least a few times. However, sometimes, the following connection issues crop up which prevent Outlook from connecting to Exchange:

• For an automatically configured Outlook profile:

“The action cannot be completed. The connection to the Microsoft Exchange Server is unavailable. Your network adapter does not have a default gateway.”

• For a manually configured Outlook profile:

“Your Microsoft Exchange Server is unavailable”

Why these errors occur?The reason behind these errors is that, a client computer running Outlook should have a default gateway configured to allow IP traffic to flow in environment thus facilitating connection with the Exchange server. If such a gateway is not configured, Outlook will not be able to connect to its present profile. Even when you try to create a new Outlook profile, the same error will flash.

For better understanding, consider a scenario wherein you have an existing profile that’s already connected to the Exchange Server. You somehow lose the setting for your default connection gateway and to verify what the settings were, you click on Check Name in the E-mail Accounts dialog box. Outlook won’t let you achieve the task and you’ll see the following error message:

“Outlook cannot log on. Verify that you are connected to the network and are using the proper server and mailbox name. The connection to the Microsoft Exchange Server is unavailable. Your network adapter does not have a default gateway.”

Even if you ignore the default gateway aspect of the error considering it to be a client-side issue and try to connect Outlook to Exchange through RPC over HTTPS, you won’t be successful. In spite of the network being a private Hyper-V switch and all machines being in a single subnet, the gateway might be required to enable the connection.So what should one do to resolve this issue?

Steps to resolve the error:

As you might have gathered from the description of the error, you’ll need to configure the gateway to resolve this problem. But, doing that is alas, not easy and is not possible on some occasions. Hence, opting for a workaround would be much simpler. This workaround involves adding a DWORD value (named DefConnectOpts) to a registry subkey. Here’s how you can do this:

1. Go to Start -> Run. In the Open dialog box, type regedit and press Enter or click OK.2. Depending upon the version of Outlook you’re using, search for the following registry subkey:Outlook 2007:HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Outlook\RPCOutlook 2010:HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook\RPCOutlook 2013:HKEY_CURRENT_USER\Software\Microsoft\Office\15.0\Outlook\RPC3. In the ‘Edit’ menu, hover on ‘New’ and then click ‘DWORD Value’.4. Write “DefConnectOpts” and press “Enter”.5. Then right-click on “DefConnectOpts” and click on “Modify” from the pop-up menu.6. A “Value data” box will open, type 0 here and click OK.7. Quit the Registry Editor.

What we actually did by the above procedure is that we disabled the current Outlook version’s connection logic and forced it to use the previous version’s connection logic. So now, the gateway configuration will no longer be validated when we try to connect Outlook to Exchange.

Make sure you backup the registry before modifying it this way and follow the steps mentioned accurately. This is because the above steps modify the registry and serious problems can occur if you do it incorrectly. Such modification directly impacts the Exchange server database (EDB) files which if get corrupt can lead to data loss. Subsequently, to repair corrupt edb you’ll need proficientEDB Repair Software to repair exchange database. Such software can efficiently repair corrupt edb file and protect you from data loss.

ConclusionThe issue described in this article is a rare one and it is important to remember that Outlook – Exchange connection can fail due to many reasons. Always be careful while making workarounds through the registry since they directly impact your Exchange database. Backup your registry before modifying it and always keep third-party recovery software at hand to repair exchange database if any disaster happens.